The need to store digital files, documents, pictures, images and other data continues to increase rapidly. In connection with the electronic storage of data, various data storage systems have been devised for the rapid and secure storage of large amounts of data. Such systems may include one or a plurality of storage devices that are used in a coordinated fashion. Systems in which data can be distributed across multiple storage devices such that data will not be irretrievably lost if one of the storage devices (or in some cases, more than one storage device) fails are also available. Systems that coordinate operation of a member of individual storage devices can also provide improved data access and/or storage times. Examples of systems that can provide such advantages can be found in the various RAID (redundant array of independent disks) levels that have been developed. Whether implemented using one or a plurality of storage devices, the storage provided by a data storage system can be treated as one or more storage volumes.
In order to facilitate the availability of desired data, it is often advantageous to maintain different versions of a data storage volume. Indeed, data storage systems are available that can provide at least limited data archiving through backup facilities and/or snapshot facilities. The use of snapshot facilities greatly reduces the amount of storage space required for archiving large amounts of data.
Snapshots provide a versatile feature that is useful for data recovery operations, such as backup and recovery of storage elements. However, traditional backup systems are limited by snapshot system requirements and restrictions. More specifically, backup systems using snapshot applications for backups typically have to configure backup settings based on the features and parameters defined by the snapshot application. Most backup systems perform systematic backups (e.g., daily, weekly, monthly, etc.) of a data storage volume. The frequency of the backups generally depends upon the use of the storage volume and whether a significant amount of data changes on a regular basis. Furthermore, most backup systems utilize only a fixed number of snapshots. With this restriction, backup systems are generally required to delete the oldest snapshot prior to creating a new snapshot that represents the current point-in-time of the data storage volume. This is cumbersome to backup system managers because each time a new snapshot is created it is assigned new attributes such as a World Wide Name (WWN), Logical Unit Number (LUN), Serial Number, and the like, which requires the backup system manager to reconfigure the backup application for the new snapshot volume information. Furthermore, since, in most cases, the volume looks like a new volume to the backup application, one cannot perform incremental backups due to the fact that the backup application does not know about the “new” volume.